Automated laboratory conveyor systems are utilized to transport various types of specimens between various work stations, and a storage or archive area. In order to provide efficient and effective storage, various types of storage racks have been provided in the prior art, for supporting a plurality of specimen tubes in spaced apart vertical orientation, for storage and retrieval by a robotic arm.
These prior art storage racks suffer several problems. The conventional prior art rack consists of a plurality of holes or "wells" formed in a solid piece of material or in a wire mesh. In order to permit a robotic arm to easily place a specimen tube within each well, the diameter of the well must be sufficiently greater in diameter than the diameter of the specimen tube to permit placement, even if the robotic arm is not directly aligned above the well. However, the hole cannot be increased in diameter without effecting the storage position of the specimen tube within the well. If the well diameter is too great, the specimen tube will be tipped to one side, and will be difficult to retrieve by the robotic arm. Thus, the size of the well diameter in conventional racks is limited by the amount of angular displacement from vertical which is permitted by the particular robotic arm to retrieve a specimen tube within the well.
A related problem concerns containment of spillage from a specimen tube which is cracked or damaged within the rack. A sufficient amount of space around the entire cylindrical surface of the specimen tube is desirable, so that any spillage is retained within the well supporting the tube. Thus, a large diameter well is preferable to a well having a diameter which is only slightly greater than the diameter of the specimen tube. In addition, it is desirable to have the specimen tube centered within the well, rather than leaning against a side of the well, such that spillage from a location above the upper surface of the rack will run down the side of the specimen tube and into the well, rather than on to the top of the rack.
Finally, storage racks are conventionally transported within a storage unit, or between storage units and conveyor systems. Any movement of the rack permits the possibility of tipping or inverting of the rack. Unless the specimen tubes are restrained within the rack in some fashion, they are susceptible of falling out of the rack and becoming either lost or broken.